Based on the input-output method, this study utilized the Eora database to assess carbon emissions and interregional transfer patterns within the manufacturing industry and its sub-sectors across the Belt and Road Initiative (BRI) countries from 2007 to 2017. The structural decomposition analysis was employed to identify the key driving factors underlying changes in embodied carbon emissions, while the effects of five distinct trade-related mechanisms on the embodied carbon emissions within industrial chains of key BRI countries were explored in depth. The results indicate that embodied carbon dioxide emissions within the manufacturing industry along the BRI increased by 25.19% over the study period, while a net emission reduction of 361.09Mt was achieved, reflecting a transition towards a consumption-driven emissions structure. Embodied carbon dioxide emissions within the manufacturing sector have increasingly shifted from mid-end manufacturing industries, such as Petroleum, Chemical and Non-Metallic Mineral Products(C7), Metal Products(C8), and Electrical and Machinery(C9) to downstream sectors, including Agriculture (C1), Food and Beverages (C4), C9, and Construction (C14). In addition, the embodied emission outflows from upstream energy industries, particularly Electricity, Gas and Water (C13), to manufacturing industries such as C4and C9has intensified. Therefore, the development of the manufacturing sector along the BRI needs to place greater emphasis on cross-border collaborative emission reduction across upstream and downstream industries. For the manufacturing industry as a whole in the BRI region, the per capita demand effect was the dominant factor of embodied carbon emissions, contributing an increase of 4323.27Mt, while the emission intensity effect exerted a substantial mitigation influence, reducing emissions by 3199.96Mt. Although the key drivers of embodied carbon emissions differ across major BRI countries, the forward linkage effect universally promotes emissions, while the backward linkage effect suppresses them. This contrast underscores the critical importance of developing green supply chains within international trade networks. Accordingly, this study proposes targeted policy recommendations for the low-carbon transition of the manufacturing industry along the BRI, highlighting the need for differentiated emission reduction strategies tailored to national and sectoral conditions.